Answer:
13 l of 15%, 13 l of 25%, 26 l of 70%
Step-by-step explanation:
solutions:
final solution:
This includes 0.45*52l= 23.4 l acid
Let's assume:
- amount of 15% solution= x
- amount of 25% solution= y
- amount of 70% solution= z
- and we have z=2y
so there are 2 equation:
or
- x+y+2y= 52 ⇒ x+3y= 52 ⇒ x= 52- 3y
- 0.15x+1.65y=23.4
- 0.15*(52-3y)+1.65y=23.4
- 7.8-0.45y+1.65y=23.4
- 1.2y=23.4-7.8
- 1.2y= 15.6
--------
- x= 52- 3*13= 13 l
- z= 2y= 2*13= 26 l
Answer: Choice C) Star shaped symbol
We can rotate the star symbol 90 degrees to have it line up with its original image. The before and after images would be identical after doing such a rotation. So this figure has rotational symmetry.
The other figures would change if we rotated them some angle x such that
, so they do not have rotational symmetry.
We have to draw the model for 42 divide 7 . In order to draw the model we use below steps.
- Draw 7 boxes to represent 7 groups.
- Assume 42 as the number which represents the total of these 7 groups.
- Put a question mark at the first box.
Attached is the model to represents 42 divide 7 .
In the question mark we should put 6. Hence, when we add 6 to 7 times that will be equal to 42.
There are 525600 minutes in a regular year
There are 527040 minutes in a leap year
I hope that's help !
Answer:
d
Step-by-step explanation: